As for why your H is being MEAN to you, it's because you popping on his radar 'reminds' him that he has a wife which bursts his fantasy bubble with the OW. He just doesn't want any reminders of you. Tough luck, bud. You're a MARRIED man!
Try not to take it personally. I know, I know. Easier said than done. Here's the thing...it's in the very early stages of an A where the WAS puts on the blinders and all the focus is on OM/OW. So when the LBS intrudes on their radar, it is like a fly in their soup bowl.